local modem = peripheral.wrap("top")

local channel = 65533
local id = os.getComputerID()

if not modem.isOpen(channel) then
    modem.open(channel)
end

while true do
    local e, v1, v2, v3, v4, v5 = os.pullEvent()
    if  e == "modem_message" and
        v2 == channel and
        v3 == 0 then
        modem.transmit(channel, id, v4)
    end
end

